Avocado Production in Asia and the Pacific - United Nations in ...

4. ESTABLISHMENT OF ORCHARDS
If an avocado plantation is to be established in a relatively new area, the varieties to
be selected for planting should belong to both A and B groups and their flowering must
overlap. The proportion of A and B group varieties can be 1:1 or 2:1.
Avocado is planted out to a distance of 6 to 12 metres depending on the vigour of
variety and its growth habit. For varieties having a spreading type of growth, like Fuerte, a
wider spacing should be given. In areas prone to excess water, they should be planted on
mounds as avocados cannot withstand waterlogging. In Sikkim, a planting distance of 10 x
10 metres on hills slopes (on half-moon terraces) is preferred and planting is done in June-
July. Pits of 90 x 90 centimetres are dug during February-March, and filled with farmyard
manure and top soil (1:1 ratio) before planting. In Coorg, a region of Karnataka state, they
have been planted also as one of the mixed crops in a primarily coffee-based cropping
system.
5. CARE AND MANAGEMENT OF ORCHARDS
Pruning is rarely practised except with upright varieties such as Pollock. In spreading
varieties like Fuerte, branches are thinned and shortened. Heavy pruning has been found to
promote excessive vegetative growth, consequently reducing the yield.
Sprinkler irrigation has been reported to improve the fruit size and oil percentage;
also, it advances harvesting time. Irrigation at intervals of three to four weeks during the dry
months is beneficial to avocado. To avoid moisture stress during winter season, mulching
with dry grass/dry leaves is desirable. Flooding is undesirable as it promotes root rot
incidence.
Avocados need heavy manuring, and application of nitrogen has been found to be
most essential. In general, young avocado trees should receive N, P 2 O 5 and K 2 O in a
proportion of 1:1:1 and older trees in the proportion of 2:1:2. At a pH of above 7, iron
deficiency symptoms may appear, which may be corrected by applying iron chelate at the
rate of 35 g/tree.
Various micronutrients (Fe, Zn, B) have profound influences on tree growth, nutrient
uptake and yield of avocado. Integrated nutrient management with inorganic fertilizer,
supplemented by organic manuring, is advocated for avocado.
In Sikkim, the soil is deficient in nitrogen, zinc and boron. Application of urea in
two split doses, in March/April and September/October (just before and after the onset of the
monsoon) is recommended. Foliar application of zinc sulphate (0.5 per cent) may be
undertaken in April-May, and other fertilizers applied in soil during March-April. A
tentative fertilizer schedule recommended for Sikkim (Upadhyay and Srivastava, 1996) is
shown in Table 2.
27